Recycled polyethylene terephthalate compositions, fibers and articles produced therefrom, and methods for producing same

ABSTRACT

In one aspect, the invention relates to recycled polyethylene terephthalate compositions, fibers and articles produced therefrom, and methods for producing same. In a further aspect, the invention relates to homogenized post-consumer polyethylene terephthalate. In a further aspect, the invention relates to extruded polymer compositions, polymer mixtures, fibers, and/or Bulked Continuous Filament fibers comprising post-consumer polyethylene terephthalate. In a further aspect, the invention relates to processes for preparing recycled polyethylene terephthalate compositions. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityto U.S. patent application Ser. No. 15/077,521 filed Mar. 22, 2016,which is a continuation and claims the benefit of U.S. patentapplication Ser. No. 14/285,143 filed May 22, 2014 (now U.S. Pat. No.9,309,609), which is a continuation of and claims the benefit of U.S.patent application Ser. No. 12/570,773 filed Sep. 30, 2009 (now U.S.Pat. No. 8,735,457), which claims the benefit of priority to U.S.Provisional Application No. 61/101,663, filed on Sep. 20, 2008. Theaforementioned applications are hereby incorporated herein by referencein their entireties.

BACKGROUND

Polyethylene terephthalate (PET) resins exhibit toughness, clarity, goodbarrier properties, lightweight, design flexibility, chemicalresistance, and good shelf-life performance. Consequently, PET is widelyused in the packaging industry, for example, in manufacturing ofbeverage bottles. Further, PET is environmentally friendly, since it canbe recycled.

Conventional recycling processes for post-consumer PET (PCPET), however,typically fail to provide materials satisfactory for extrusion intofiber, for example, bulked continuous filament (BCF), especiallycompared to virgin PET (VPET). For example, recycled polyethyleneterephthalate (RPET) provided by conventional recycling techniques canexhibit unsatisfactory streaking when used in carpet applications andcan break during processing steps.

Therefore, there remains a need for methods and compositions thatovercome these deficiencies and that effectively provide recycledpolyethylene terphthalate compositions, fibers, and articles.

SUMMARY

In accordance with the purpose(s) of the invention, as embodied andbroadly described herein, the invention, in one aspect, relates torecycled polyetheylene terphthalate compositions, fibers and articlesproduced therefrom, and methods for producing same.

Disclosed are extruded polymer compositions comprising polyethyleneterephthalate present as up to about 100% curbside post-consumerpolyethylene terephthalate by weight and balance virgin polyethyleneterephthalate.

Also disclosed are polymer mixtures comprising polyethyleneterephthalate present as up to about 100% homogeneous curbsidepost-consumer polyethylene terephthalate by weight and balance virginpolyethylene terephthalate.

Also disclosed are fibers extruded from polyethylene terephthalatepresent as up to about 100% curbside post-consumer polyethyleneterephthalate by weight and balance virgin polyethylene terephthalate.

Also disclosed are Bulked Continuous Filament extruded fibers comprisinga polymer composition of polyethylene terephthalate present as up toabout 100% curbside post-consumer polyethylene terephthalate by weightand balance virgin polyethylene terephthalate.

Also disclosed are Bulked Continuous Filament fibers extruded from apolymer composition comprising polyethylene terephthalate present as upto about 100% curbside post-consumer polyethylene terephthalate byweight and balance virgin polyethylene terephthalate.

Also disclosed are homogenized curbside post-consumer polyethyleneterephthalate.

Also disclosed are processes for preparing recycled polyethyleneterephthalate compositions comprising the step of blending curbsidepost-consumer polyethylene terephthalate to homogeneity prior to mixingwith virgin polyethylene terephthalate.

Also disclosed are processes for preparing recycled polyethyleneterephthalate compositions comprising the step of mixing homogeneouscurbside post-consumer polyethylene terephthalate with virginpolyethylene terephthalate prior to extrusion of the mixture.

Also disclosed are processes for preparing a recycled polyethyleneterephthalate composition comprising the step of extruding a mixture ofhomogeneous curbside post-consumer polyethylene terephthalate and virginpolyethylene terephthalate

Also disclosed are processes for preparing recycled polyethyleneterephthalate compositions comprising the step of blending curbsidepost-consumer polyethylene terephthalate to homogeneity prior toextrusion.

Also disclosed are processes for preparing recycled polyethyleneterephthalate compositions comprising the steps of blending curbsidepost-consumer polyethylene terephthalate to homogeneity; optionally,crystallizing the homogeneous curbside post-consumer polyethyleneterephthalate; drying the homogeneous curbside post-consumerpolyethylene terephthalate; mixing the homogeneous curbsidepost-consumer polyethylene terephthalate with virgin polyethyleneterephthalate; and extruding the mixture.

Also disclosed are the products of the disclosed processes.

While aspects of the present invention can be described and claimed in aparticular statutory class, such as the system statutory class, this isfor convenience only and one of skill in the art will understand thateach aspect of the present invention can be described and claimed in anystatutory class. Unless otherwise expressly stated, it is in no wayintended that any method or aspect set forth herein be construed asrequiring that its steps be performed in a specific order. Accordingly,where a method claim does not specifically state in the claims ordescriptions that the steps are to be limited to a specific order, it isno way intended that an order be inferred, in any respect. This holdsfor any possible non-express basis for interpretation, including mattersof logic with respect to arrangement of steps or operational flow, plainmeaning derived from grammatical organization or punctuation, or thenumber or type of aspects described in the specification.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying figures, which are incorporated in and constitute apart of this specification, illustrate several aspects and together withthe description serve to explain the principles of the invention.

FIG. 1 is a flowchart showing an exemplary method for processingpost-consumer polyethylene terephthalate (PET) bulked continuousfilament (BCF).

FIG. 2 is a schematic showing side- and cross-sectional views of barrierextrusion screws that can be useful in the disclosed processes.

Additional advantages of the invention will be set forth in part in thedescription which follows, and in part will be obvious from thedescription, or can be learned by practice of the invention. Theadvantages of the invention will be realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

DESCRIPTION

The present invention can be understood more readily by reference to thefollowing detailed description of the invention and the Examplesincluded therein.

Before the present compounds, compositions, articles, systems, devices,and/or methods are disclosed and described, it is to be understood thatthey are not limited to specific synthetic methods unless otherwisespecified, or to particular reagents unless otherwise specified, as suchmay, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular aspects only andis not intended to be limiting. Although any methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, example methods andmaterials are now described.

All publications mentioned herein are incorporated herein by referenceto disclose and describe the methods and/or materials in connection withwhich the publications are cited. The publications discussed herein areprovided solely for their disclosure prior to the filing date of thepresent application. Nothing herein is to be construed as an admissionthat the present invention is not entitled to antedate such publicationby virtue of prior invention. Further, the dates of publication providedherein can be different from the actual publication dates, which canrequire independent confirmation.

A. Definitions

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a composition,” “afiber,” or “a step” includes mixtures of two or more such functionalcompositions, fibers, steps, and the like.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint. It is also understood that there are a number of valuesdisclosed herein, and that each value is also herein disclosed as“about” that particular value in addition to the value itself. Forexample, if the value “10” is disclosed, then “about 10” is alsodisclosed. It is also understood that each unit between two particularunits are also disclosed. For example, if 10 and 15 are disclosed, then11, 12, 13, and 14 are also disclosed.

As used herein, the terms “optional” or “optionally” means that thesubsequently described event or circumstance can or can not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

As used herein, the term “residue” refers to a moiety that is theresulting product of the chemical species in a particular reactionscheme or subsequent formulation or chemical product, regardless ofwhether the moiety is actually obtained from the chemical species. Thus,an ethylene glycol residue in a polyester refers to one or more—OCH₂CH₂O— units in the polyester, regardless of whether ethylene glycolwas used to prepare the polyester. Similarly, a sebacic acid residue ina polyester refers to one or more —CO(CH₂)₈CO— moieties in thepolyester, regardless of whether the residue is obtained by reactingsebacic acid or an ester thereof to obtain the polyester.

As used herein, the term “polymer” refers to a relatively high molecularweight organic compound, natural or synthetic, whose structure can berepresented by a repeated small unit, the monomer (e.g., polyethylene,rubber, cellulose). Synthetic polymers are typically formed by additionor condensation polymerization of monomers. Homopolymers (i.e., a singlerepeating unit) and copolymers (i.e., more than one repeating unit) aretwo categories of polymers.

As used herein, the term “copolymer” refers to a polymer formed from twoor more different repeating units (monomer residues). By way of exampleand without limitation, a copolymer can be an alternating copolymer, arandom copolymer, a block copolymer, or a graft copolymer. It is alsocontemplated that, in certain aspects, various block segments of a blockcopolymer can themselves comprise copolymers.

As used herein, the term “molecular weight” (MW) refers to the mass ofone molecule of that substance, relative to the unified atomic mass unitu (equal to 1/12 the mass of one atom of carbon-12).

As used herein, the term “number average molecular weight” (M_(n))refers to the common, mean, average of the molecular weights of theindividual polymers. M_(n) can be determined by measuring the molecularweight of n polymer molecules, summing the weights, and dividing by n.M_(n) is calculated by:

${{\overset{\_}{M}}_{n} = \frac{\sum_{i}{N_{i}M_{i}}}{\sum_{i}N_{i}}},$wherein N_(i) is the number of molecules of molecular weight M_(i). Thenumber average molecular weight of a polymer can be determined by gelpermeation chromatography, viscometry (Mark-Houwink equation), lightscattering, analytical ultracentrifugation, vapor pressure osmometry,end-group titration, and colligative properties.

As used herein, the term “weight average molecular weight” (M_(w))refers to an alternative measure of the molecular weight of a polymer.M_(w) is calculated by:

${{\overset{\_}{M}}_{w} = \frac{\sum_{i}{N_{i}M_{i}^{2}}}{\sum_{i}{N_{i}M_{i}}}},$wherein N_(i) is the number of molecules of molecular weight M_(i).Intuitively, if the weight average molecular weight is w, and a randommonomer is selected, then the polymer it belongs to will have a weightof w, on average. The weight average molecular weight can be determinedby light scattering, small angle neutron scattering (SANS), X-rayscattering, and sedimentation velocity.

As used herein, the terms “polydispersity” and “polydispersity index”refer to the ratio of the weight average to the number average(M_(w)/M_(n)).

As used herein, the terms “polyethylene terephthalate” and “PET” referto a thermoplastic polyester resin that can exist both as an amorphous(transparent) and as a semicrystalline (opaque and white) material. PETcan also exist as a semicrystalline transparent material, as used in theside walls of PET bottles. In such aspects, the crystals are smallerthan the wavelength of visible light and thus do not make the materialopaque and white. PET can be represented with the following structuralformula:

PET can be used in synthetic fibers; beverage, food and other liquidcontainers; thermoforming applications; and engineering resins, often incombination with glass fiber. Its monomer can be synthesized by theesterification reaction between terephthalic acid and ethylene glycolwith water as a byproduct, or the transesterification reaction betweenethylene glycol and dimethyl terephthalate with methanol as a byproduct.Polymerization can be through a polycondensation reaction of themonomers with ethylene glycol as the byproduct.

The terms “polyethylene terephthalate” and “PET” include both PETpolymers and copolymers. For example, PET can be provided as a copolymerhaving, in addition to terephthalic acid residues and ethylene glycolresidues, additional isophthalic acid residues and/orcycloheanedimethanol residues. It is also understood that PET polymerand/or copolymer can be provided as part of a polymer blend.

As used herein, the terms “new” and “virgin,” when used in connectionwith polymeric material, refer to polymeric material that is notpost-consumer (or post-industrial) polymeric material.

As used herein, the term “post-consumer,” when used in connection withpolymeric material, refers to polymeric material collected from the endconsumer of a material stream. Post-consumer (or post-industrial)polymeric material can, in contrast to virgin polymeric material,typically contain impurities resulting from use in consumer (orindustrial) products prior to recovery for recycling.

As used herein, the term “crystallized,” when used in connection withpolyethylene terephthalate, refers to polymer that has been subjected tocrystallizing conditions (e.g., heat to a temperature above the glasstransition temperature (T_(g)) of polyethylene terephthalate) sufficientto minimize or eliminate sticking during a subsequent processing step,for example, a drying step.

As used herein, the term “homogeneous” when used in connection withpolymeric material, refers to material mechanically blended to a uniformstate sufficient to minimize or eliminate streaking in textiles such ascarpet and/or breaking of extruded material during a subsequentprocessing step, for example, an extrusion step, twisting, or tufting.

As used herein, the term “deposit” when used in connection withpost-consumer polymeric material, refers to post-consumer polymericmaterial that is deposit grade. Deposit grade is the highest qualitybaled post-consumer polymer, for example, PET. Deposit polymer mainlycomes from PET soda bottles collected in one of about nine U.S. states,wherein a bottle deposit system encourages their return. Depositmaterials command a premium price in the marketplace.

As used herein, the term “curbside” when used in connection withpost-consumer polymeric material, refers to post-consumer polymericmaterial that is generally lower quality baled post-consumer polymer,for example, PET. Curbside polymer mainly comes from soda, water, andcustom PET bottles, usually including other types of resins. Sand,glass, PVC, and dirt are common contaminants.

As used herein, the term “pellet” when used in connection withpost-consumer polymeric material, refers to post-consumer polymericmaterial that is provided in a pelletized form, similar to the form ofcommercial virgin polymer.

As used herein, the term “flake” when used in connection withpost-consumer polymeric material, refers to post-consumer polymericmaterial that is provided in irregular, flaked form, typically frommechanically comminuted polymer material.

As used herein, the term “staple fiber” refers to relatively shortlengths of fiber, typically chopped from continuous filament intolengths of 4″ to 7½″. The lengths can be spun together to create strandsof yarn.

As used herein, the term “bulked continuous filament fiber” refers tocontinuous strands of synthetic fiber formed into yarn bundles of agiven number of filaments and typically texturized to increase bulk andcover.

Disclosed are the components to be used to prepare the compositions ofthe invention as well as the compositions themselves to be used withinthe methods disclosed herein.

These and other materials are disclosed herein, and it is understoodthat when combinations, subsets, interactions, groups, etc. of thesematerials are disclosed that while specific reference of each variousindividual and collective combinations and permutation of thesecompounds can not be explicitly disclosed, each is specificallycontemplated and described herein. For example, if a particular compoundis disclosed and discussed and a number of modifications that can bemade to a number of molecules including the compounds are discussed,specifically contemplated is each and every combination and permutationof the compound and the modifications that are possible unlessspecifically indicated to the contrary. Thus, if a class of molecules A,B, and C are disclosed as well as a class of molecules D, E, and F andan example of a combination molecule, A-D is disclosed, then even ifeach is not individually recited each is individually and collectivelycontemplated meaning combinations, A-E, A-F, B-D, B-E, B-F, C-D, C-E,and C-F are considered disclosed. Likewise, any subset or combination ofthese is also disclosed. Thus, for example, the sub-group of A-E, B-F,and C-E would be considered disclosed. This concept applies to allaspects of this application including, but not limited to, steps inmethods of making and using the compositions of the invention. Thus, ifthere are a variety of additional steps that can be performed it isunderstood that each of these additional steps can be performed with anyspecific embodiment or combination of embodiments of the methods of theinvention.

It is understood that the compositions disclosed herein have certainfunctions. Disclosed herein are certain structural requirements forperforming the disclosed functions, and it is understood that there area variety of structures that can perform the same function that arerelated to the disclosed structures, and that these structures willtypically achieve the same result.

B. Recycled Polyethylene Terephthalate

In one aspect, the invention relates to recycled polymer compositionsprepared from post-consumer polyethylene terephthalate. For example, arecycled polymer composition can be prepared from homogenized curbsidepost-consumer polyethylene terephthalate, which can be present inpelletized form, in flaked form, or in a combination thereof. As furtherexamples, recycled polymer compositions can be provided as polymermixtures, as extruded polymer compositions, as fibers, and/or as bulkedcontinuous filament fibers.

In one aspect, a recycled post-consumer polymer (e.g., curbsidepost-consumer polyethylene terephthalate) composition can be extruded toprovide a bulked continuous filament fiber.

It is understood that the disclosed compositions, mixtures, and fiberscan be employed in connection with the disclosed fibers, methods, anduses.

1. Mixtures and Compositions

In one aspect, the invention relates to polymer mixtures comprisingpolyethylene terephthalate present as up to about 100% homogeneouscurbside post-consumer polyethylene terephthalate by weight and balancevirgin polyethylene terephthalate.

In a further aspect, the invention relates to extruded polymercompositions comprising polyethylene terephthalate present as up toabout 100% curbside post-consumer polyethylene terephthalate by weightand balance virgin polyethylene terephthalate.

2. Fibers

In a still further aspect, the invention relates to fibers extruded frompolyethylene terephthalate present as up to about 100% curbsidepost-consumer polyethylene terephthalate by weight and balance virginpolyethylene terephthalate. For example, the fiber can be a BulkedContinuous Filament extruded fiber comprising a polymer composition ofpolyethylene terephthalate present as up to about 100% curbsidepost-consumer polyethylene terephthalate by weight and balance virginpolyethylene terephthalate. As a further example, the fiber can be aBulked Continuous Filament fiber extruded from a polymer compositioncomprising polyethylene terephthalate present as up to about 100%curbside post-consumer polyethylene terephthalate by weight and balancevirgin polyethylene terephthalate.

3. Post-Consumer Content

In one aspect, at least a portion of the disclosed compositions comprisepost-consumer polyethylene terephthalate. In one aspect, thepost-consumer polyethylene terephthalate is curbside post-consumerpolyethylene terephthalate. In one aspect, the balance of thecomposition can be virgin polyethylene terephthalate.

In a further aspect, polyethylene terephthalate is present as at leastabout 5%, at least about 10%, at least about 15%, at least about 20%, atleast about 25%, at least about 30%, at least about 35%, at least about40%, at least about 45%, at least about 50%, at least about 55%, atleast about 60%, at least about 65%, at least about 70%, at least about75%, at least about 80%, at least about 85%, at least about 90%, or atleast about 95% curbside post-consumer polyethylene terephthalate byweight.

In a further aspect, polyethylene terephthalate is present as up toabout 5%, up to about 10%, up to about 15%, up to about 20%, up to about25%, up to about 30%, up to about 35%, up to about 40%, up to about 45%,up to about 50%, up to about 55%, up to about 60%, up to about 65%, upto about 70%, up to about 75%, up to about 80%, up to about 85%, up toabout 90%, or up to about 95% curbside post-consumer polyethyleneterephthalate by weight.

In further aspects, the polyethylene terephthalate can be present asabout 100% curbside post-consumer polyethylene terephthalate by weight,or virgin polyethylene terephthalate can be absent.

4. Raw Materials

In one aspect, the raw materials can be selected for compatibility withthe disclosed processes. For example, curbside post-consumerpolyethylene terephthalate can be present in pelletized form, in flakedform, or a mixture thereof.

As a further example, curbside post-consumer polyethylene terephthalateflakes can be selected for one or more of the following specifications:Bulk density (lb/ft3) of 20-27; Moisture content (%) of <1.0%; Floatablecontamination (ppm) of <25; PVC contamination (ppm) of <150; Metalcontamination (ppm) of <10; Other non-melting particles (ppm) of <50;Green pet contamination (ppm) of <5000; Light blue contamination (ppm)of <75,000; Low melt material (PETG) (ppm) of <50; Black PET (ppm) of<50; Pressure rise (psi per pound) of <75 psi/lb; b Color values asmeasured by a HunterLabs Spectrophotometer of 0-3 units, and/or L Colorvalues as measured by a HunterLabs Spectrophotometer of greater than 50units.

As a further example, curbside post-consumer polyethylene terephthalatepellets can be selected for one or more of the following specifications:bulk density greater than about 45 lbs/ft3; pressure rise of less thanabout 35 psi/lb with IV solution viscosity of greater than 0.70; andpellet count of about 50-70 pellets/gram; Hunter Color L value(crystallized pellet) of greater than about 60; and Color B value ofless than about 6.

Commercial suppliers of suitable post-consumer polyethyleneterephthalate flake/pellet materials can be found in the directory ofthe Association of Postconsumer Plastic Recyclers.

5. Impurities

Post consumer polyethylene terephthalate, for example curbside PET, cancontain various impurities, for example, sand, glass, colorants, paper,other polymers (e.g., PVC, PETG), metals, adhesives, syrups, fillers,and dirt. In various aspects, impurities can be present in post-consumerpolyethylene terephthalate as one or more of floatable contamination;PVC contamination; metal contamination; other non-melting particles;green PET contamination; light blue PET contamination; low melt material(such as PETG); and black PET contamination. In contrast, suchimpurities are typically substantially absent from virgin PET.

In a further aspect, one or more impurities can be present as up toabout 10 ppm, about 25 ppm, about 50 ppm, about 100 ppm, about 500 ppm,about 1000 ppm, about 5000 ppm, about 1%, about 2%, about 3%, about 5%,about 7.5%, or about 10% by weight. In a further aspect, total impuritycontent can be up to about 10 ppm, about 25 ppm, about 50 ppm, about 100ppm, about 500 ppm, about 1000 ppm, about 5000 ppm, about 1%, about 2%,about 3%, about 5%, about 7.5%, or about 10% by weight.

In a further aspect, one or more impurities can be present as less thanabout 10 ppm, about 25 ppm, about 50 ppm, about 100 ppm, about 500 ppm,about 1000 ppm, about 5000 ppm, about 1%, about 2%, about 3%, about 5%,about 7.5%, or about 10% by weight. In a further aspect, total impuritycontent can be up to about 10 ppm, about 25 ppm, about 50 ppm, about 100ppm, about 500 ppm, about 1000 ppm, about 5000 ppm, about 1%, about 2%,about 3%, about 5%, about 7.5%, or about 10% by weight.

6. Additives

The disclosed compositions can further comprise one or more additivesknown to those of skill in the art. That is, one of skill can readilymodify one or more properties of the disclosed compositions by selectionand inclusion of one or more additives. As examples, the one or moreadditives can be selected from plasticizers, opacifiers, nucleatingagents, colorants, dyes, clarifiers, diluents, and/or fillers.

In various aspects, one or more additives can be present as up to about0.5%, up to about 1%, up to about 2%, up to about 3%, up to about 4%, upto about 5%, or up to about 10% of the composition by weight.

In various aspects, one or more additives can be present as less thanabout 0.5%, less than about 1%, less than about 2%, less than about 3%,less than about 4%, less than about 5%, or less than about 10% of thecomposition by weight.

C. Uses

The disclosed compositions exhibit utility in various articles commonlymanufactured from polymer compositions, in particular, from polyethyleneterephthalate compositions. In one aspect, the compositions can beprovided as fibers, for example, as bulked continuous filament fibers.These fibers can be employed in textile articles, including carpet.Thus, in one aspect, the invention relates to a carpet comprising adisclosed polymer composition or a disclosed fiber. In a further aspect,the invention relates to a carpet comprising a product of a disclosedprocess.

It is understood that the disclosed uses can be employed in connectionwith the disclosed fibers, compositions, methods, and mixtures.

D. Processes for Preparing Recycled Polyethylene Terephthalate

In one aspect, the invention relates to a process for preparing arecycled polyethylene terephthalate composition comprising the step ofblending curbside post-consumer polyethylene terephthalate tohomogeneity prior to mixing with virgin polyethylene terephthalate. In afurther process, the invention relates to a process for preparing arecycled polyethylene terephthalate composition comprising the step ofmixing homogeneous curbside post-consumer polyethylene terephthalatewith virgin polyethylene terephthalate prior to extrusion of themixture. In a further process, the invention relates to a process forpreparing a recycled polyethylene terephthalate composition comprisingthe step of extruding a mixture of homogeneous curbside post-consumerpolyethylene terephthalate and virgin polyethylene terephthalate. In afurther process, the invention relates to a process for preparing arecycled polyethylene terephthalate composition comprising the step ofblending curbside post-consumer polyethylene terephthalate tohomogeneity prior to extrusion.

It is understood that the disclosed processes can be employed inconnection with the disclosed fibers, compositions, mixtures, and uses.

1. System Components

As illustrated in FIG. 1, the method for processing post-consumer PETcan exemplarily comprise at least one of: at least one blending means,at least one crystallizer, at least one drying means, at least oneextruder, and at least one spinnerette. Additionally, at least onefiltration means and/or at least one mixing means can be present.

In one aspect, the at least one blending means 2 can comprise at leastone conventional active blender with an auger, configured to increasethe uniformity of the post-consumer PET flakes and/or pellets containedtherein. In another aspect, the at least one blending means can furthercomprise at least one conventional blending silo 4, 5 configured tofurther improve blended flake and/or pellet uniformity. In one aspect,the at least one blending silo can include a recirculation means and atleast one flow channel to improve uniformity, as known in the arts. Inanother aspect, the at least one blending silo can be dimensioned toprocess post-consumer PET flake and/or pellet lot sizes of up to 500,000pounds. For example, in one aspect, the at least one blending silo 4, 5can be dimensioned to process flake and/or pellet lot sizes of about250,000 pounds. One non-limiting example of a suitable blending silo isa Directed Flow Channel (DFC) Blender which is commercially availablefrom Columbian TecTank, 5400 Kansas Avenue, Kansas City, Kans. 66106.Another non-limiting example is the 1500 cu. ft model batch mixer fromSprout Waldron (Muncy, Pa. USA).

The at least one blending means, in one aspect, can further comprise atleast one bulk bag unloading means 1 configured to allow direct mixingof a plurality of infeed lots into the at least one blending silo. Inanother aspect, the at least one bulk bag unloading means can beconfigured to allow direct mixing of up to four different infeed lotsinto the at least one blending silo. In a further aspect, this directmixing can be customized to allow for optimal blending, if desired. Inanother aspect, the at least one bulk bag unloading means 1 can be aconventional, commercially available bulk bag unloader.

In one aspect, the at least one crystallizer 6 can be a conventional,commercially available crystallizer configured for crystallizing virginPET and/or post-consumer PET.

In another aspect, the drying means 8 can comprise a conventional,commercially available dryer system configured for drying virgin PETand/or post-consumer PET.

The at least one extruder 9 can comprise an extruder screw and anextruder mixing element 10. One embodiment of the extruder screw isillustrated in FIG. 2. In one aspect, the extruder screw 20 can comprisea conventional barrier screw 22 configured such that pressure and/ortemperature fluctuations are minimized in the fiber extrusion process.In another aspect, the extruder screw can comprise a barrier flight 24introduced in a transition section between the feed zone 26, whereinmaterial to be processed is introduced into the extruder screw, and ametering zone 28, wherein material to be processed is introduced into afiltering means. The barrier flight can define two channels, a meltchannel 30 and a solids channel 32, and can have clearance between a tipof the barrier flight and a wall of the barrel containing the screw.This clearance can allow molten virgin PET and/or post-consumer PET topass from the solids channel into the melt channel. One example of suchan extruder screw is the DSB-1 barrier screw commercially available fromDavis-Standard LLC, #1 Extrusion Drive, Pawcatuck, Conn. 06379. Suitablemodels of the DSB-1 include a Moderate Work Barrier Screw having a 30:1Length/Diameter ratio and a deep feed, and a Moderate/Low Work BarrierScrew having a 34:1 L/D ratio.

In one aspect, when compared to extrusion of virgin PET, extrusion of ablend of post-consumer PET and virgin PET blend can require one or moreof deepening the feed section of the extruder screw, use of a barrierflighted mixing screw and increased power availability in the drivesystem for the extruder. In another aspect, an extrusion profile is usedthat minimizes heat generation along the length of the barrel (whilestill assuring adequate heat input for melting the different variants ofpost-consumer PET flakes).

The extruder mixing element 10 can comprise a conventionalloss-in-weight mixing unit having at least one hopper mounted adjacentthe at least one extruder 9. Two examples of such an extruder mixingelement are the XGGCYUMFFK01 or XLGCYYUMKLX01s mixers commerciallyavailable from the Process Control Corporation. The at least one hoppercan comprise a mixing means to introduce virgin PET and/or post-consumerPET into the extruder screw.

The at least one filtering means 12 can comprise a conventional plasticmelt filtration unit comprising an automatic backflushing filteringsystem configured to minimize downtime of the extruder. In one aspect,the at least one filtering means can be able to process at least 1,000pounds of post-consumer PET per hour per filter. In another aspect, theat least one filtering means can preferably process at least 1,000pounds of post-consumer PET per hour per filter. For example, about1,000 pounds of post-consumer PET per hour per filter, about 2,500pounds of post-consumer PET per hour per filter, about 5,000 pounds ofpost-consumer PET per hour per filter, or about 10,000 pounds ofpost-consumer PET per hour per filter. In yet another aspect, the atleast one filtering means can remove particles as small as about 50microns from the meltstream. However, it is contemplated that the atleast one filtering means can remove from the meltstream, for example,particles that are about 10 microns in size, about 25 microns in size,about 50 microns in size, or about 100 microns in size. One example of asuitable filtering means is a Gneuss RSF-60 Rotary Filtration System,which is commercially available from Gneuss Inc., 10820-G, IndependencePointe Parkway, Matthews, N.C. 28105.

The at least one spinnerette can be a conventional spinnerettecomprising at least one melt pump configured to pump melted virgin PETand/or post-consumer PET to at least one spinner, to produce fiber.

2. Assembly and Use

With reference to FIG. 1, a system for processing post-consumer PET canbe assembled to comprise any or all of the components as describedabove. In one aspect, the at least one bulk bag unloading means 1 can beoperatively coupled to the blending means 2, so that a plurality ofinfeed lots can input post-consumer PET into the blending means.Optionally, virgin PET can be introduced can be input into the blendingmeans, alone or in combination with the post-consumer PET. In anotheraspect, the blending means, which can comprise the at least one activeblender and/or the at least one blending silo 4, the at least onecrystallizer 6, the at least one drying means 8, and the at least oneextruder 9 can be operative coupled serially. Thus, virgin PET and/orpost-consumer PET pellets and/or flakes can be transported from the atleast one bulk bag unloading means to the at least one blending means,from the at least one blending means to the at least one crystallizer,from the at least one crystallizer to the at least one drying means, andfrom the at least one drying means to the at least one extruder. As canbe appreciated by one of skill in the art, the pellets and/or flakes maybe transported pneumatically, conveyed on a belt, be gravity fed, and/ortransported by other means.

In another aspect, the at least one filtering means 12 can be attachedto the at least one extruder to filter contaminants from the meltstream,before entering the spinnerette for production of fiber. As also can beappreciated by one of skill in the art, components processing moltenvirgin PET and/or post-consumer PET can be in fluid communication witheach other by, for example, at least one pipe.

In use, in one aspect, post-consumer PET pellets and/or flakes in bulkbags can be unloaded by the at least one bulk bag unloading means 1 intothe at least one blending means 2, such as the at least one activeblender. The at least one active blender, in another aspect, can have anauger for blending the post-consumer PET pellets and/or flakes. Inanother aspect, the post-consumer PET pellets and/or flakes can betransported from the at least one active blender into the at least oneblending silo 4,5 until a homogenous mixture of post-consumer PET isformed therein the silo. In still another aspect, the post-consumer PETpellets and/or flakes can be diverted into a plurality of blending silos4,5 so that a greater amount of material can be processed at a giventime. In yet another aspect, the amount of time necessary for homogenousblending to occur can vary depending on the model of active blenderand/or blending silo used, and can be provided by the respectiveequipment manufacturer. In one aspect, homogenous blending can beachieved in about 2 hours. In another aspect, homogenous blending can beachieved in about 36 hours. In yet another aspect, homogenous blendingcan be achieved in about 48 hours.

In one aspect, in order to test the homogeneity of a blend, a knownamount of PET having a known color can be inserted into the at least oneactive blender and/or the at least one blending silo. A known amount ofan exogenous tracing marker can also be inserted into the at least oneactive blender and/or the at least one blending silo. An exogenoustracing marker can be provided with a known property (e.g., color,fluorescence, etc.) readily measureable in samples taken from themixture. The PET having a known color and the exogenous tracing markercan be blended together and the resulting mixture can be checkedperiodically for marker distribution levels. The blending can continueuntil the percentage of marker in a sample is substantially equal to thepercentage of marker in the at least one active blender and/or the atleast one blending silo.

In a further aspect, the homogenized blend of post-consumer PET can thenbe transported to the at least one crystallizer 6. The manufacturer ofthe crystallizer can supply a temperature and time required tocrystallize the post-consumer PET, which can prevent the post-consumerPET from sticking within the system. After crystallization, in yetanother aspect, the post-consumer PET pellets and/or flakes can enterthe at least one drying means 8 for removal of moisture from thepost-consumer PET. Again, the manufacturer of the respective dryingmeans can provide a required drying time. Alternatively, a moisturesensor can be used to determine if the post-consumer PET is sufficientlydry for further processing. In one aspect, the post-consumer PET can bedried to a moisture level of about 25-200 ppm. In another aspect, thepost-consumer PET can be dried to a moisture level of about 50-100 ppm.In one aspect, residence time post-consumer PET in the drying means canbe at least five hours. In a further aspect, the dew point in the dryingmeans can be −20° F.

In a further aspect, upon exiting the at least one drying means, thepost-consumer PET pellets and/or flakes can enter the at least onehopper of the extruder mixing element of the at least one extruder 9. Atthis point, in one aspect, virgin PET can also be added to anotherhopper of the extruder mixing element. The at least one hopper can feedthe blended post-consumer PET and virgin PET into the extruder at thedesired mixture ratio by following the extruder mixing elementmanufacturer instructions. In another aspect, the percentage ofpost-consumer PET present in the mixture of post-consumer PET and virginPET that is fed into the extruder can be at least about 5%, at leastabout 10%, at least about 15%, at least about 20%, at least about 25%,at least about 30%, at least about 35%, at least about 40%, at leastabout 45%, at least about 50%, at least about 55%, at least about 60%,at least about 65%, at least about 70%, at least about 75%, at leastabout 80%, at least about 85%, at least about 90%, or at least about 95%post-consumer PET by weight. In yet another aspect, the percentage ofpost-consumer PET present in the mixture of post-consumer PET and virginPET that is fed into the extruder can be up to about 5%, up to about10%, up to about 15%, up to about 20%, up to about 25%, up to about 30%,up to about 35%, up to about 40%, up to about 45%, up to about 50%, upto about 55%, up to about 60%, up to about 65%, up to about 70%, up toabout 75%, up to about 80%, up to about 85%, up to about 90%, or up toabout 95% post-consumer PET by weight.

In one aspect, the virgin PET/post-consumer PET mixture can enter thefeed zone 26 of the barrier screw 22 of the at least one extruder 9. Thebarrier screw can rotate, urging the mixture into a barrier zone whereinthe virgin PET/post-consumer PET mixture can melt into a liquid that canenter the melt channel 30 of the barrier screw. The melted mixture canthen be urged into the metering zone 28 of the barrier screw, configuredto feed the melted mixture at an appropriate pressure to the at leastone filtering means.

In one aspect, the extruder profile of the at least one extruder can beset to temperatures between about 250-350° C. In still another aspect,the extruder profile can be set to temperatures between about 280-305°C. In another aspect, the extruder profile can be set to a temperatureto produce a melt temperature between about 275-325° C. at the end ofthe extruder. In still another aspect, the extruder profile can be setto a temperature to produce a melt temperature between about 285-300° C.at the end of the extruder.

In one aspect, the extruder control pressure can be set at a pressurethat produces adequate polymer supply to the spin pack metering pumps ofthe at least one spinnerette. In another aspect, melt pressurevariations related to filtration equipment should be kept less than 25bar to minimize polymer melt temperature variation,

In another aspect, the filtering means can remove any unmelted particlesand/or other contaminants from the melted mixture. This can, in oneaspect, help prevent weak spots from being created in the fiber. Thefiltered, melted mixture can then be introduced into the spinnerette,wherein the melted mixture is urged through a die to form a fiber. Thefiber can be cooled and wound onto a bobbin for further processing.

In one aspect, the at least one spinnerette can have a polymer spin pumpspeed having less than 5% variation from target setting across the line.In another aspect, the at least one spinnerette can have a polymer spinpump speed having less than 1% variation from target setting across theline. According to another aspect, the texturizing system roll speeds ofthe at least one spinnerette can be controlled to +/−4 m/min, and thetexturizing system roll temperatures can be controlled to within +/−4°C. In another aspect, the texturizing system roll speeds of the at leastone spinnerette can be controlled to +/−2 m/min and the texturizingsystem roll temperatures can be controlled to within +/−2° C. In yetanother aspect, the spinning draw ratio of the at least one spinnerettecan be between 3.0 and 5.5 In another aspect, the spinning draw ratio ofthe at least one spinnerette can be between 3.7 and 4.4 In one aspect,the texturizer jet pressures and temperatures of the at least onespinnerette can be controlled to +/−4° C. and less than 1.0 bar range.In another aspect, the texturizer jet pressures and temperatures of theat least one spinnerette can be controlled to +/−2° C. and less than 0.5bar range. The tack system and pressure can be controlled within a 1.0bar range, according to one aspect. In another aspect, the tack systemand pressure can be controlled within a 0.5 bar range.

In one aspect, the fiber formed from by the virgin PET/post-consumer PETmixture, referred to as singles yarn, can be processed, for example,into yarn by twisting, as commonly known in the arts. In a furtheraspect, the singles yarn produced can be wound at a tension betweenabout 100-300 grams. In a further aspect, finish oil can be added aspercentage of weight between about 1.0-1.5%. In a further aspect,substantially all of the singles yarn of the twisted yarn can be formedfrom the virgin PET/post-consumer PET mixture. In yet another aspect, atleast one of the singles yarn of the twisted yarn can be formed from thevirgin PET/post-consumer PET mixture. In still another aspect, anynumber of the singles yarn of the twisted yarn can be formed from thevirgin PET/post-consumer PET mixture.

In one aspect, the twisted yarn containing at least one singles yarnproduced by the virgin PET/post-consumer PET mixture can be tufted intocarpet, also as commonly known in the arts. In a further aspect,substantially all of the twisted yarn of the carpet can be formed fromsingles yarn formed from the virgin PET/post-consumer PET mixture. Inyet another aspect, at least one of the twisted yarns of the carpet canbe formed from singles yarn formed from the virgin PET/post-consumer PETmixture. In still another aspect, any number of the twisted yarns of thecarpet can be formed from singles yarn formed from the virginPET/post-consumer PET mixture.

3. Selecting Raw Materials

In one aspect, curbside post-consumer PET can be selected so that it canmeet or exceed at least one of the following specifications: Bulkdensity (lb/ft3) of 20-27; Moisture content (%) of <1.0%; Floatablecontamination (ppm) of <25; PVC contamination (ppm) of <150; Metalcontamination (ppm) of <10; Other non-melting particles (ppm) of <50;Green pet contamination (ppm) of <5000; Light blue contamination (ppm)of <75,000; Low melt material (PETG) (ppm) of <50; Black PET (ppm) of<50; Pressure rise (psi per pound) of <75 psi/lb; b Color values asmeasured by a HunterLabs Spectrophotometer of 0-3 units, and/or L Colorvalues as measured by a HunterLabs Spectrophotometer of greater than 50units.

4. Blending

In one aspect, the disclosed processes can include a blending step tohomogenize the profile of post-consumer PET input to the extruder. Forexample, at least one blending silo can comprise a recirculation line torecirculate, and thereby blend, post-consumer PET therein. In anotherexample, the at least one blending silo can comprise multiple flowchannels to help blend post-consumer PET therein. The blending step, inone aspect, can reduce the variation in particle size, color variation,copolymer content, and contamination to provide a more homogeneous blendof post-consumer PET to the extruder. In another aspect, the blendingstep can comprise blending the post-consumer PET therein the blendingsilo until a desired level of homogenization is reached. In yet anotheraspect, the blending step can comprise blending the post-consumer PETtherein the blending silo for a period of time effective to homogenatethe mixture. In still another aspect, the blending step can compriseblending the post-consumer PET therein the blending silo for a specificperiod of time, for example, 2 hours, 4 hours, 8 hours, 12 hours, 16hours, 24 hours, 36 hours, or 72 hours.

5. Crystallization

In one aspect, the disclosed process can include a crystallization step.For example, the post-consumer PET pellets and or flakes can be heatedto an elevated temperature while being constantly stirred and/oragitated for a period of time. In another aspect, the crystallizationstep can take place in a crystallizer, comprising a heatable containerwith a series of paddles or agitators therein. In other aspects, thecrystallization step can take place in a crystallizer comprising a hot,fluidized bed for keeping the pellets and/or flakes apart.Crystallization can be accomplished by employing commercially availableequipment known to those of skill.

6. Drying

In one aspect, the disclosed processes can include a drying step. Forexample, the post-consumer PET pellets and/or flakes can be dryed in aconventional PET dryer. In one aspect, the post-consumer PET pelletsand/or flakes can be dryed to a moisture level. In a further aspect,post-consumer PET pellets and/or flakes can be dryed for a period oftime. Drying can be performed, for example, to achieve a moisture levelof less than about 5%, less than about 4%, less than about 3%, less thanabout 2%, less than about 1%, less than about 0.5%, less than about0.25%, less than about 1000 ppm, less than about 500 ppm, or less thanabout 100 ppm. In a further aspect, moisture levels can be reduced tofrom about 50 ppm to about 100 ppm. In a further aspect, moisture levelscan be reduced to a level sufficient to minimize or eliminate the effectof moisture during subsequent processing steps.

7. Mixing

In one aspect, the disclosed processes can include a mixing step. Forexample, the post-consumer PET pellets and/or flakes can be mixed withvirgin PET pellets and/or flakes to create a post-consumer PET/virginPET mixture. In one aspect, the percentage of post-consumer PET in themixture can be at least about 5%, at least about 10%, at least about15%, at least about 20%, at least about 25%, at least about 30%, atleast about 35%, at least about 40%, at least about 45%, at least about50%, at least about 55%, at least about 60%, at least about 65%, atleast about 70%, at least about 75%, at least about 80%, at least about85%, at least about 90%, or at least about 95% post-consumer PET byweight. In another aspect, the percentage of post-consumer PET presentin the mixture of post-consumer PET and/or virgin PET that is fed intothe extruder can be up to about 5%, up to about 10%, up to about 15%, upto about 20%, up to about 25%, up to about 30%, up to about 35%, up toabout 40%, up to about 45%, up to about 50%, up to about 55%, up toabout 60%, up to about 65%, up to about 70%, up to about 75%, up toabout 80%, up to about 85%, up to about 90%, or up to about 95%post-consumer PET by weight.

In a further aspect, the mixing step can occur in a mixer. In oneaspect, the mixer can be an extruder mixing element comprising at leastone hopper, which feeds the extrusion means. The at least one hopper cancomprise a mixing means to introduce virgin PET and/or post-consumer PETinto the extruder screw at a specified ratio. In a further aspect, themixer can be a mixing means within the extruder.

The extruder mixing element 10 can comprise a conventionalloss-in-weight mixing unit having at least one hopper mounted adjacentthe at least one extruder 9. Two examples of such an extruder mixingelement are the XGGCYUMFFK01 or XLGCYYUMKLX01 mixers commerciallyavailable from the Process Control Corporation. The at least one hoppercan comprise a mixing means to introduce virgin PET and/or post-consumerPET into the extruder screw.

8. Extrusion

In one aspect, the disclosed processes can include an extrusion step.For example, the post-consumer PET/virgin PET mixture can be extruded toproduce fiber. In one aspect, the extrusion step can take place in anextruder comprising a screw (e.g., a barrier screw), a filtering means,and/or a spinnerette. Extrusion can be accomplished by employingcommercially available equipment known to those of skill.

9. Additives

In one aspect, the disclosed processes can include the addition ofadditives to the post-consumer PET blend and/or the post-consumerPET/virgin PET mixture. As an example, and without limitation, additivescan include dyes, colorants, UV absorbers, plasticizers, opacifiers,nucleating agents, clarifiers, diluents, and/or fillers. Additives canbe added, for example, contemporaneously with mixing.

E. Experimental

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thecompounds, compositions, articles, devices and/or methods claimed hereinare made and evaluated, and are intended to be purely exemplary of theinvention and are not intended to limit the scope of what the inventorsregard as their invention. Efforts have been made to ensure accuracywith respect to numbers (e.g., amounts, temperature, etc.), but someerrors and deviations should be accounted for. Unless indicatedotherwise, parts are parts by weight, temperature is in ° C. or is atambient temperature, and pressure is at or near atmospheric.

In the disclosed examples, twisting and heatsetting, tufting, and dyeingand finishing processes were performed at the same specificationsregardless of the percentage of post-consumer PET being processed. Thus,all post-consumer PET samples were processed under the same twisting andheatsetting, tufting, and dyeing and finishing process specifications asthe 100% virgin PET control. Although these conditions were employed toprovide the disclosed compositions and articles, it is understood that,unless otherwise stated, these conditions are not limiting and can, ifdesired, be modified to suit other manufacturing needs.

1. Preparation of Yarn and Carpet from Fiber Formed from Post-ConsumerPet Curbside Flakes

Fiber containing 50% post-consumer PET, 65% post-consumer PET, 85%post-consumer PET, and 100% RPET was formed, as described above, fromcurbside grade flakes. As illustrated in Table 1, trials were run withunblended (i.e., not homogenized) curbside flake from two suppliers.Trials were repeated with curbside flake from two suppliers blendedtogether. All trials processed successfully with no significantdifferences in runability or product physicals except for a shift incolor in the compositions (e.g., fibers) produced from curbside flake.The results of the experiments as compared to a control lot containing0% post-consumer PET are illustrated in Tables 2-8.

TABLE 1 Trial Description RPET Insertion Trial # Raw Material Supplier #rate Blended 1 Curbside flake C1 50% No 2 Curbside flake C1 65% No 3Curbside flake C1 85% No 4 Curbside flake C1 100% No 5 Curbside flake C250% No 6 Curbside flake C2 65% No 7 Curbside flake C2 85% No 8 Curbsideflake C2 100% No 9 Curbside flake C1/C2 50% Yes 10 Curbside flake C1/C265% Yes 11 Curbside flake C1/C2 85% Yes 12 Curbside flake C1/C2 100% YesControl 0% N/A

This fiber was processed into yarn, as is commonly known in the arts,and compared to a sample of yarn containing 0% post-consumer PET. Theresult of this comparison is tabulated in Tables 2, 3, 4 and 5. The yarnproduced from fiber containing 50% post-consumer PET, 65% post-consumerPET, 85% post-consumer PET and 100% post-consumer PET was tufted intocarpet and compared to a sample of carpet containing 0% post-consumerPET. The resulting comparison is illustrated in Tables 6-8.

The test results of the singles yarns formed are illustrated in Table 2.Denier, Finish on Yarn (“FOY”), Modification Ratio (“MR”), Tenacity atPeak Load, Elongation at Peak Load, Nodes per Meter, Crimp, Bulk, and IVSolution Viscosity are conventional industry measurements used to definea yarn. As can be appreciated by one of skill in the arts, and asillustrated in Table 2, there were no significant difference notedbetween the control sample and the post-consumer PET samples withrespect to these physical properties. However, drying times and/ortemperatures were adjusted to minimize any impact that increasingpost-consumer PET flake content (for both blended and unblended samples)would have on the Modification Ratio and IV. Color of the yarn wasmeasured by a HunterLabs Spectrophotometer. As illustrated in Table 2,as the percentage of post-consumer PET in the yarn increased, the Dbincreased, indicating that the yarn became more yellow as the percentageof post-consumer PET increased. Note also that the Db standard deviationfor blended yarn was lower than for the unblended samples.

The average Db standard deviation of yarn formed from unblended curbsideflakes supplied by the first supplier (Trials 1-4) was 0.28, and theaverage Db standard deviation of yarn formed from unblended curbsideflakes supplied by the second supplier (Trials 5-8) was 0.20. Theaverage Db standard deviation of yarn formed from curbside flakessupplied by the first supplier and the second supplier and blendedtogether (Trials 9-12) was 0.17.

TABLE 2 % Post-consumer PET Curbside Flake Singles Yarn Data Trial FOY %Tenacity Avg % Avg Nodes/ % % IV Sol. Db # Denier OWF MR (g/d) TenacityElong Elong m Crimp Bulk Viscosity Db StdDev 1 1226 1.42 2.76 1.95 39.425 10.8 29.7 0.6305 0.71 0.13 2 1265 1.41 2.91 2.1 42.6 25 10.3 30.10.6677 1.34 0.37 3 1258 1.42 2.82 2.17 45.3 27 10.8 34.6 0.6534 2.600.17 4 1267 1.49 2.79 2.23 2.1125 44 42.825 29 10.9 34.7 3.17 0.46 51246 1.39 2.64 2.20 44.4 25 10.6 31.5 0.6882 0.54 0.12 6 1269 1.32 2.782.44 44.3 26 9.56 32.5 0.6898 0.48 0.10 7 1264 1.26 2.69 2.15 39.2 2510.6 34 0.6513 0.84 0.23 8 1259 1.24 2.72 2.18 2.2425 42.7 42.65 27 10.633.9 0.6679 2.01 0.37 9 1248 1.42 2.75 2.28 43.3 25 9.72 32.2 0.6641 0.80.15 10 1247 1.41 2.91 2.33 45.5 26 9.90 30.8 0.6782 1.18 0.15 11 12431.34 2.84 2.28 36.4 29 9.18 29.3 0.6694 2.24 0.21 12 1260 1.35 2.88 2.302.2975 40.7 41.475 29 9.39 29.7 0.6900 1.90 0.16 Control 1252 1.38 2.782.48 37.8 25 9.22 23.6 0.6812

Single filaments were removed from the singles yarns and tested as well.These results are illustrated in Table 3. Excluded Pulls were excludedfrom the tests because these filaments had a tenacity and/or elongationless than 20% of the average, according to ASTM standards. These samplesillustrate that there were improvements in average tenacity, elongation,and their standard deviations with the blended samples. Additionally,blended sample had a lower number of excluded pulls. Increasing levelsof post-consumer PET flake, while impacting color, did not have asignificant impact on tenacity and elongation, particularly for theblended samples, and blending the flakes resulted in lower variabilityin molecular composition.

The average elongation standard deviation of yarn formed from unblendedcurbside flakes supplied by the first supplier (Trials 1-4) was 11.42,and the average tenacity standard deviation of this yarn was 0.777. Theaverage elongation standard deviation of yarn formed from unblendedcurbside flakes supplied by the second supplier (Trials 5-8) was 10.58,and the average tenacity standard deviation of this yarn was 0.629. Theaverage elongation standard deviation of yarn formed from curbsideflakes supplied by the first supplier and the second supplier andblended together (Trials 9-12) was 7.79, and the average tenacitystandard deviation of yarn formed from these flakes was 0.423.

TABLE 3 % Post-consumer PET Curbside Flake Singles Filament DataTenacity Excl. @ Break Tenacity Elongation @ Elongation Trial # Pulls(g/dn) StdDev Break StdDev 1 7 2.540 0.723 31.580 11.344 2 4 2.688 0.85032.873 11.437 3 N/A 4 5 2.064 0.759 25.999 11.472 5 0 3.233 0.286 36.8447.813 6 2 3.023 0.596 34.827 8.109 7 7 2.545 0.749 32.092 12.650 8 72.562 0.884 34.616 13.731 9 0 3.200 0.342 40.612 6.974 10 4 3.001 0.34641.116 7.972 11 5 2.472 0.625 31.987 9.679 12 1 3.186 0.380 36.866 6.533Control 0 3.160 0.427 36.363 7.730

The singles yarns were each twisted with at least one other like yarn(i.e., if a yarn was formed from 50% post-consumer PET provided bySupplier 1, it was twisted with at least one other yarn formed from 50%post-consumer PET provided by Supplier 1) and heatset, as is commonlyknown in the arts, and compared to a sample of twisted yarn containing0% post-consumer PET. The result of this comparison is tabulated inTables 4 and 5.

As can be appreciated by one of skill in the art, and as illustrated inTable 4, there were differences in color between the samples withblended samples (trial numbers 8-12) having less average variation in b*(blue/yellow) and Db* (blue/yellow) on heatset samples from thebeginning and the end of the heatset operation, as measured by aHunterLabs Spectrophotometer. Also, the average b* and Db* values forthe blended samples were between the unblended C1 and C2 samples. Thepositive impact of blending is shown in both reduced variation in colorfor the samples from the beginning and end of each run and averaging outthe color of the different flake providers.

The average b* value of yarn formed from unblended curbside flakessupplied by the first supplier (Trials 1-4) was 3.31, and the averageDb* value of this yarn was 1.95. The average b* value of yarn formedfrom unblended curbside flakes supplied by the second supplier (Trials5-8) was 2.43, and the average Db* value of this yarn was 1.06. Theaverage b* value of yarn formed from curbside flakes supplied by thefirst supplier and the second supplier and blended together (Trials9-12) was 3.16, and the average Db* value of yarn formed from theseflakes was 1.79.

There was an average b* difference of 0.36 and an average Db* differenceof 0.47 for yarn from unblended curbside flakes supplied by the firstand second supplier (Trials 1-8). This average b* difference was reducedto 0.22 and the average Db* difference was reduced to 0.38 when the yarnwas formed from curbside flakes supplied by the first supplier and thesecond supplier and blended together (Trials 9-12). The reduction invariation in color for the samples from the beginning and end of eachsample, and the averaging of the contaminants and copolymer content ofthe different flake providers makes the yarn less variable over timewith changes in sources.

TABLE 4 % Post-consumer PET Curbside Flake Heatset Yarn Color Diff. b*Diff. Db* Trial Avg begin and Avg begin and # Position b* b* end Db* Db*end 1 Begin HS 1.69 0.16 1 End HS 2.00 1.85 0.31 0.80 0.48 0.64 2 BeginHS 2.22 0.68 2 End HS 2.64 2.43 0.42 1.44 1.06 0.76 3 Begin HS 4.43 2.893 End HS 4.08 4.26 0.35 2.88 2.89 0.01 4 Begin HS 4.36 2.83 5 End HS5.09 4.73 0.73 3.89 3.36 1.06 5 Begin HS 1.87 0.33 5 End HS 1.82 1.850.05 0.61 0.47 0.28 6 Begin HS 1.44 −0.10 6 End HS 1.34 1.39 0.10 0.130.02 0.23 7 Begin HS 3.07 1.54 7 End HS 2.23 2.65 0.84 1.03 1.29 0.51 8Begin HS 3.85 2.32 8 End HS 3.79 3.82 0.06 2.59 2.46 0.27 9 Begin HS2.13 0.59 9 End HS 2.28 2.21 0.15 1.07 0.83 0.48 10 Begin HS 2.66 1.1210 End HS 3.04 2.85 0.38 1.83 1.48 0.71 11 Begin HS 3.98 2.45 11 End HS3.90 3.94 0.08 2.70 2.58 0.25 12 Begin HS 3.78 2.24 12 End HS 3.51 3.650.27 2.31 2.28 0.07 Control 0.00 0.00

Table 5 illustrates the average tenacity and elongation of the heatsetyarns. As can be seen, the yarns formed from a blended post-consumer PETcurbside flake had improved tenacity and elongation when compared tosimilar unblended yards. As can be appreciated by one of skill in thearts, the average tenacity and elongation for all the samples was onlymarginally lower that the control and has no impact on the carpet formedtherefrom.

TABLE 5 Post-consumer PET Curbside Flake Heatset Yarn Tenacity andElongation Avg HS Avg HS Trial # Tenacity Elongation 1 2.483 48.888 22.544 44.015 3 2.535 51.351 4 2.455 44.307 5 2.572 44.087 6 2.520 46.1107 2.461 50.394 8 2.444 49.361 9 2.600 48.291 10 2.545 51.828 11 2.53753.664 12 2.516 48.999 Control 2.623 56.249

The yarn produced from the trials was tufted into carpets and comparedto a sample of carpet containing 0% post-consumer PET. For example,carpet Trial 1 was produced only from yarn formed from 50% post-consumerPET curbside flake that was not blended to homogeneity. Carpet Trial 12was produced only from yarn formed from 100% post-consumer PET curbsideflake provided by two suppliers blended together. Each carpet was testedagainst a control having 0% post-consumer curbside flakes. Tables 6-8tabulate the results.

Table 6 illustrates that there were no significant differences betweenthe blended samples, the unblended samples, and the control with respectto stain resistant. In each test, various industry-standard stainingagents, such as mustard, coffee, red wine, red #40, povidone-iodine wereapplied to the samples. A score of between 1 and 10 was given to eachsample to indicate the carpets resistance to the staining agents.

TABLE 6 Post-consumer PET Curbside Flake Carpet Test Data Povidone-Trial # Red 40 Mustard iodine Coffee Red Wine 1 10.0 10.0 9.0 10.0 10.02 10.0 10.0 10.0 10.0 10.0 3 10.0 10.0 10.0 10.0 10.0 4 10.0 10.0 9.010.0 10.0 5 10.0 10.0 10.0 10.0 10.0 6 10.0 10.0 9.0 10.0 10.0 7 10.010.0 9.0 10.0 10.0 8 10.0 10.0 9.0 10.0 10.0 9 10.0 10.0 9.0 10.0 10.010 10.0 10.0 9.0 10.0 10.0 11 10.0 10.0 9.0 10.0 10.0 12 10.0 10.0 8.010.0 10.0 Control 10.0 10.0 9.0 10.0 10.0

As indicated in Table 7, the carpets were evaluated under a variety ofconventional industry tests. Xenon, Ozone, Crock and NOx areconventional color-related tests, as measured on a scale of 1 to 5, with5 being no visible change from control, and 3 being a passing grade. DE(CMC) and Grey Scale are conventional measures of a carpet's resistanceto soiling. Hexapod is a conventional measure of the wearability of thecarpet, while Pill test is a conventional measure of flammability. Ascan be seen in Table 7, there were there were no significant differencesbetween the blended samples, the unblended samples, and the control withrespect to these tests.

Stitches, Pile Height and Pile Weight and are conventional industrymeasurements of the construction of a carpet. As illustrated in Table 8,there were no significant differences between the blended samples, theunblended samples, and the control with respect to the construction ofthe carpets. Streaks, Tips, Hand, and Finish are conventional industrymeasurements of the appearance of a carpet. While all samples of carpetcontaining post-consumer PET rated lower for streaking than the control,carpets formed from blended samples had less streaking than that formedfrom unblended samples. In general, carpets containing post-consumer PEThad better hand, less texture and were more dull as the percentage ofPET increased. However, based upon improvements in the homogeneity ofyarn color as extruded and improved yarn streak ratings, the overallprocess and system components were shown to be effective.

TABLE 7 Post-consumer PET Curbside Flake Carpet Test Data AcceleratedSoiling DE(CMC) Grey Scale 40 hour Crock* 2 cycle 2 Cycle 4K HexapodPerform* Pill Trial Soiled Cleaned Soiled* Cleaned* Xenon* Wet DryOzone* Nox* Warp Fill Aver Test 1 1.89 0.78 3.5 4.0 4.0 5.0 4.5 3.5 3.53.3 3.0 3.2 8/8 2 1.81 0.88 3.0 4.0 4.0 5.0 4.5 3.5 3.5 3.3 2.8 3.1 8/83 1.92 1.06 3.0 4.0 4.0 5.0 4.5 3.0 3.5 3.5 3.0 3.3 8/8 4 1.73 1.12 3.54.5 4.0 5.0 4.5 3.5 4.0 3.3 2.8 3.1 8/8 5 2.14 0.97 3.5 4.5 4.5 5.0 4.53.5 3.5 2.8 2.8 2.8 8/8 6 2.21 0.85 3.5 4.5 4.0 5.0 4.5 3.5 4.0 3.3 3.03.2 8/8 7 2.03 0.78 3.0 4.0 4.0 5.0 4.5 3.5 3.5 3.3 2.8 3.1 8/8 8 1.840.98 3.0 4.0 4.0 5.0 4.5 3.5 3.5 3.0 2.8 2.9 8/8 9 1.92 1.51 3.0 4.0 3.55.0 4.5 3.5 4.0 3.0 3.0 3.0 8/8 10 1.56 0.99 3.0 4.0 4.0 5.0 4.5 4.0 4.03.0 3.4 3.2 8/8 11 1.74 0.84 3.0 4.0 4.0 5.0 4.5 4.0 4.0 3.0 3.0 3.0 8/812 2.32 1.28 3.0 4.0 4.0 5.0 4.5 4.0 4.5 3.0 2.8 2.9 8/8 Control 1.900.80 3.0 4.0 4.0 5.0 4.5 3.5 4.0 3.3 3.0 3.2 8/8

TABLE 8 Post-consumer PET Curbside Flake Carpet Construction and FinishData Streak Pile Pile Trial into Avg Avg Avg Avg Height Wgt # PileStreak Hand Hand Tips Tips Finish Finish (inch) Stitch (oz) 1 5.50 6.426.33 6.00 31/32 63 43.61 2 6.50 6.17 6.17 5.75 31/32 62.5 43.60 3 6.506.08 6.17 5.75 31/32 62.5 43.85 4 5.50 6.00 6.08 6.19 6.08 6.19 5.505.75 31/32 61 43.82 5 6.00 6.58 6.50 6.33 31/32 62.5 43.86 6 6.50 6.256.42 6.17 31/32 63 43.90 7 6.00 6.17 6.00 5.50 31/32 62 43.70 8 5.506.00 6.08 6.27 5.83 6.19 5.50 5.88 31/32 63 43.63 9 6.50 6.58 6.50 6.4231/32 62 43.76 10 6.50 6.08 6.17 5.92 31/32 64 43.78 11 6.50 5.83 6.176.00 31/32 63 43.87 12 6.00 6.38 5.92 6.10 5.75 6.15 5.67 6.00 31/3263.5 43.70 Control 7.00 7.00 7.00 7.00 31/32 62 43.95

In other experiments, fiber containing 25% post-consumer PET was formedas described above from curbside flakes. The flake lot was pre-blendedand pre-crystallized, and dried on a fiber line. The trial processedsuccessfully with no significant differences in runability or productphysicals except for a shift in color (approximately 1.5 units yellow).The results of the experiment are, as compared to a control lotcontaining 0% post-consumer PET is illustrated in Tables 9 and 10. Colorwas stable throughout the 25% post-consumer PET curbside flake lot.

TABLE 9 Post-consumer PET Curbside Flake Yarn Data Lot Denier TenacityElongation NPM Bulk FOY 0% Post- 1255 2.20 41.26 24.69 9.7 1.29 ConsumerPET 25% Post- 1258 2.23 44.56 1.14 Consumer Curbside Flake PET

TABLE 10 Post-consumer PET Curbside Flake Color Data Lot DL Da Db DE 0%Post-Consumer PET .0133 .035 −.23 .3267 25% Post-Consumer Curbside Flake−.5325 −.310 1.5425 2.2313 PET

The 25% post-consumer PET curbside flake lot processed with little to novariation in physical properties when compared to the standard exceptfor color, as noted above. The curbside flake lot, as expected by aperson of skill in the art, required increased backflushing of thefiltering means because of the additional contaminants present in thecurbside grade material. In this experiment, the initial pressure acrossthe filtering means with new (clean) screens in place was 175 bar. Thebackflush pressure was set to 185 bar. With this setting, the curbsideflakes backflushed approximately every two hours.

2. Discussion of Results

As can be seen in the above Tables reflecting the testing performed onyarn and carpet from fiber formed from post-consumer PET CurbsideFlakes, in general, post-consumer PET flakes blended together performedmore like the control than did non-blended flakes. Additionally,post-consumer PET flakes blended from multiple sources performed morelike the control than did non-blended flakes.

It is contemplated that the blending of post-consumer PET flakes lowersthe percentage of any one impurity in a given sample of thepost-consumer PET flakes. For example, if a first lot of post-consumerPET flakes from a supplier has light blue contamination, yet is stillwithin the specifications, another lot of post-consumer PET flakes froma second supplier is not likely to have the same level of light bluecontamination, and the blended product will have some level of lightblue contamination in between the two lots. Thus, the blended productwill have an improved level of light blue contamination when compared tothe first lot.

In one aspect, it is contemplated that if the suppliers of post-consumerPET flakes are separated by a geographic distance, then the suppliersare more likely to have different contaminants and copolymer content inthe flakes based upon the source of bottles and their respective bottlecleaning technologies. Also, producers of virgin PET resin used to makebottles have their own specific PET formulations. In this aspect, afterblending flakes from geographically separated suppliers, anycontaminants and copolymer differences present would be present in amore uniform and/or smaller percentage than in an unblended lot from asingle supplier.

In another aspect, having contaminants present in a more uniform and/orsmaller percentage will yield a more consistent fiber. This fiber can,in turn, be used to produce more consistent goods therefrom, such as forexample and without limitation, carpet.

Thus, in one aspect, the invention relates to a polymer mixturecomprising polyethylene terephthalate present as up to about 100%homogeneous curbside post-consumer polyethylene terephthalate by weightand balance virgin polyethylene terephthalate, wherein the curbsidepost-consumer polyethylene terephthalate materials is provided by two ormore suppliers.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Otherembodiments of the invention will be apparent to those skilled in theart from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

What is claimed is:
 1. An extruded polymer composition consistingessentially of polyethylene terephthalate polymer composition, whereinthe polyethylene terephthalate polymer composition has greater than 10%by weight to about 100% by weight of homogenized curbside post-consumerpolyethylene terephthalate, or homogenized curbside post-industrialpolyethylene terephthalate, or a homogenized blend of curbsidepost-consumer and post-industrial polyethylene terephthalate, andbalance virgin polyethylene terephthalate, wherein the homogenizedcurbside polyethylene terephthalate, or homogenized curbsidepost-industrial polyethylene terephthalate, or the homogenized blend ofcurbside post-consumer and post-industrial polyethylene terephthalatecomprises at least one impurity not present in virgin polyethyleneterephthalate.
 2. The extruded polymer composition of claim 1, whereinthe polyethylene terephthalate polymer composition has at least about25% by weight of homogenized curbside post-consumer polyethyleneterephthalate, or homogenized curbside post-industrial polyethyleneterephthalate, or the homogenized blend of curbside post-consumer andpost-industrial polyethylene terephthalate.
 3. The extruded polymercomposition of claim 1, wherein the polyethylene terephthalate polymercomposition has at least about 50% by weight of homogenized curbsidepost-consumer polyethylene terephthalate, or homogenized curbsidepost-industrial polyethylene terephthalate, or the homogenized blend ofcurbside post-consumer and post-industrial polyethylene terephthalate.4. A polymer mixture consisting essentially of polyethyleneterephthalate polymer composition, wherein the polyethyleneterephthalate polymer composition has greater than 10% by weight toabout 100% by weight of homogenized curbside post-consumer polyethyleneterephthalate, or homogenized curbside post-industrial polyethyleneterephthalate, or a homogenized blend of curbside post-consumer andpost-industrial polyethylene terephthalate, and balance virginpolyethylene terephthalate, wherein the homogenized curbsidepolyethylene terephthalate, or homogenized curbside post-industrialpolyethylene terephthalate, or the homogenized blend of curbsidepost-consumer and post-industrial polyethylene terephthalate comprisesat least one impurity not present in virgin polyethylene terephthalate.5. The polymer mixture of claim 4, wherein the polyethyleneterephthalate polymer composition has at least about 25% by weight ofhomogenized curbside post-consumer polyethylene terephthalate, orhomogenized curbside post-industrial polyethylene terephthalate, or thehomogenized blend of curbside post-consumer and post-industrialpolyethylene terephthalate.
 6. The polymer mixture of claim 4, whereinthe polyethylene terephthalate polymer composition has at least about50% by weight of homogenized curbside post-consumer polyethyleneterephthalate, or homogenized curbside post-industrial polyethyleneterephthalate, or the homogenized blend of curbside post-consumer andpost-industrial polyethylene terephthalate.
 7. A carpet comprising afiber consisting essentially of polyethylene terephthalate polymercomposition, wherein the polyethylene terephthalate polymer compositionhas greater than 10% by weight to about 100% by weight of homogenizedcurbside post-consumer polyethylene terephthalate, or homogenizedcurbside post-industrial polyethylene terephthalate, or a homogenizedblend of curbside post-consumer and post-industrial polyethyleneterephthalate, and balance virgin polyethylene terephthalate, whereinthe homogenized curbside polyethylene terephthalate, or homogenizedcurbside post-industrial polyethylene terephthalate, or the homogenizedblend of curbside post-consumer and post-industrial polyethyleneterephthalate comprises at least one impurity not present in virginpolyethylene terephthalate.
 8. The carpet of claim 7, wherein thepolyethylene terephthalate polymer composition has at least about 25% byweight of homogenized curbside post-consumer polyethylene terephthalate,or homogenized curbside post-industrial polyethylene terephthalate, orthe homogenized blend of curbside post-consumer and post-industrialpolyethylene terephthalate.
 9. The carpet of claim 7, wherein thepolyethylene terephthalate polymer composition has at least about 50% byweight of homogenized curbside post-consumer polyethylene terephthalate,or homogenized curbside post-industrial polyethylene terephthalate, orthe homogenized blend of curbside post-consumer and post-industrialpolyethylene terephthalate.
 10. The carpet of claim 7, wherein the atleast one impurity comprises floatable contamination in an amount lessthan 25 ppm, PVC contamination in an amount less than 150 ppm, or acombination thereof.
 11. The carpet of claim 7, wherein the homogenizedcurbside polyethylene terephthalate, or homogenized curbsidepost-industrial polyethylene terephthalate, or the homogenized blend ofcurbside post-consumer and post-industrial polyethylene terephthalateexhibits a bulk density of 20-27 lb/ft³, a moisture content of less than1.0%, and a pressure rise of less than 75 psi/lb.
 12. The extrudedpolymer composition of claim 1, wherein the at least one impuritycomprises floatable contamination in an amount less than 25 ppm, PVCcontamination in an amount less than 150 ppm, or a combination thereof.13. The polymer mixture of claim 4, wherein the at least one impuritycomprises floatable contamination in an amount less than 25 ppm, PVCcontamination in an amount less than 150 ppm, or a combination thereof.14. A fiber comprising the extruded polymer composition of claim
 1. 15.The fiber of claim 14, wherein the fiber is a bulk continuous filament(BCF).
 16. The fiber of claim 14, wherein the at least one impuritycomprises floatable contamination in an amount less than 15 ppm, PVCcontamination in an amount less than 50 ppm, or a combination thereof.17. A fiber comprising the polymer mixture of claim
 4. 18. The fiber ofclaim 17, wherein the fiber is a bulk continuous filament (BCF).
 19. Thefiber of claim 17, wherein the at least one impurity comprises floatablecontamination in an amount less than 15 ppm, PVC contamination in anamount less than 50 ppm, or a combination thereof.